When connecting IDE devices in your computer, there are a few rules you need to know about.

• Firstly, Master and Slave devices are different for the 80-wire cables and the 40-wire cables.
• Secondly, if you don't know for sure, RTDM... (read the damn manual).

Inside your computer, you generally have two IDE hard drive controller connections (see Fig.1 below). They look this this 99% of the time but they can be different colours, usually red or blue for Ultra ATA.

Fig.1: (The smaller one on the very top is a floppy drive controller connection)

There is a Primary & Secondary connection located here. The Primary connection ALWAYS gets the 80-wire cable for your hard drive. The Secondary connection also needs an 80-wire cable when connecting to your DVD Burner. You will not be able to burn much faster than 4x speed if you use a 40-wire cable

Pictured below are the two cables, the 80-wire and the older 40-wire ATA IDE cables. As you may be able to see, the newer 80-wire cable has very small wires running from connector to connector, conversely, the 40-wire cable has thicker wires. The reason for this is that the newer standard requires the addition and separation of the wires for better signals to achieve the faster speeds.

Fig.2: A standard 80-conductor Ultra DMA IDE/ATA interface cable. Note the blue, grey and black connectors, and the 80 thin wires. The red marking on wire #1 is present (but hard to see in this photo.)

Fig.3: A standard, 40-wire IDE/ATA cable. Note the presence of three black connectors, and the 40 individual wires in the ribbon cable. Also note the red wire that marks wire #1 and hence pin #1 on each connector.

The Older Master & Slave Relationship

For the longest time, hard drives have always had a setting for a Master (or Primary) setting and Slave. The Master was always the boot drive, the drive that contained the operating system. The other drive or Slave drive was for data storage. In rare cases, using this configuration you could boot from a Slave device but we're not going to get into that here and now. The way technicians have always done it in the past with the 40-wire cable was to use the Master in the middle connection and Slave on the end. It really didn't matter much until the hard drive makers started making drives with the Cable Select option.

Connecting Your Hard Drives

40-wire Cables
On the slower, older, 40-wire ATA cables, the Master device, usually an older CD-ROM or CD writers still goes on the end, but the jumpers must be set as Slave. Did you ever buy a new CD-ROM or CD-ROM burner, open up the package and see that the jumper was already on the Slave position? It's that way for a reason. This is true even if you don't have a hard drive in the Master position. The Master for 40-wire cables goes on the the middle connector. Only older computers (the AT type) have a problem here, and again, you should read the manual that came with the motherboard or contact the maker of the system. You could try it as a Master and it may work but that's not the way it should be. If you want to use the cable select with the older drive on a 40-wire cable, you'll have to consult the maker of the drive for the instructions. There was a loose standard to put the Master drive on the end of the 40-wire cable and the Slave in the middle but that was a very loose standard. Most manufacturers (IBM, Maxtor, etc.) say that the user should set the drive using the Master and Slave jumpers on the hard drive, placing the Master in the middle and the Slave on the end.

80-wire Cables
On the ATA66/100/133 standard 80-wire cable, the Master hard drive or your boot hard drive goes on the end of the cable. This is true whether or not you use the Master/Slave style or the Cable Select style.

Fig.5

Connect your DVD writer to the secondary IDE using an 80-wire IDE cable. The coloured connector (Blue or Red) plugs into the motherboard and the black connector at the other end connects to your DVD writer that has had the jumper set to Master, as shown in Fig.6 below.

Fig.6

Install the 80-Conductor IDE Cable

The 40-pin 80-conductor cable is orientation specific. The cable connectors are colour-coded: blue or red for the host connector, black and grey for the primary and secondary disk drives.

In single drive configurations the coloured connector is connected to the motherboard and  the primary drive to the opposite end connector (Black) on the 40-pin 80-conductor cable.

The three connectors on the 80-wire cable are typically different colours and attach to specific items:

• The blue or red connector attaches to the motherboard.
• The black connector attaches to the primary, or master, drive.
• The grey connector attaches to the secondary, or slave, drive.
• All Ultra ATA/66 devices should be attached to a single channel and devices that do not support Ultra ATA/66 such as CD-ROM drives and slower CD writers should be connected to a separate channel